Knief advancing and latching means for a tobacco cutting machine



June 25, 1%6' A. RITSCHER 2,753,949

KNIFE ADVANCING AND LATCHING MEANS FOR A TOBACCO CUTTING MACHINE Filed June 1, 1953 INVENTOR:

%% BY ,awf m United States Patent KNIFE ADVANCING AND LATCHING MEANS FOR A T OBACCO CUTTING MACHINE Arthur Ritscher, Hamburg-Bergedorf, Germany, assignor to Kurt Korber & Cu. K. G., Hamburg-Bergedorf, Germany Application June 1, 1953, Serial No. 358,926

Claims priority, application Germany June 16, 1952 1 Claim. (Cl. 146-117) The invention relates to improvements in tobacco cutting machines and is particularly concerned with a device for transmitting movement to the rotary cutter head of a rotary tobacco cutter. In known cutting machines the drive of the knife head is effected continuously while the feed of the knives on the knife head is effected intermittently. The feed of the latter is effected in the known machines by devices in which for example the knives are fed forward during the rotation of the knife head by means of a cam drive through a ratchet and worm drive. In this case the device is such that the automatic feed of each single knife can be disconnected by means of a special coupling in order that the feed of the knives can be effected for example more rapidly with suitable devices.

The use of a cam drive for the intermittent feed of the knives and further the individual couplings, the number of which depends on the number of knives present, for disconnecting the knives, are expensive and a constant source of faults. This disadvantage is avoided according to the invention which consequently provides improvements.

In the arrangement according to the invention the knife head is continuously driven in the usual manner for example by means of a motor. The knife feed is however eifected no longer intermittently but likewise continuously, whereby the movement is transmitted to the knives from the same driving shaft of the knife head by means of a hollow shaft. The hollow shaft is provided externally with a worm gear which engages a worm and operates through further reduction gears. The pitch of the wheels is such that only a definite small movement or feed is obtained.

Even with the continuous feed of the knives according to the feature of the invention it is advantageous to interrupt the feed for certain periods. This however is effected in such manner that only one coupling is provided for all the knives. Thus while for example the knife head operates continuously, the knife feed can be stopped. Thereby for example the knives can be ground during a certain period.

The features of the invention are shown as a constructional example in three figures on the accompanying drawings wherein:

Fig. 1 is a section on the line CD of Fig. 2 through the knife head wherein for the sake of clearness the end plate of the knife roller is omitted.

Fig. 2 is a section on the line AB of Fig. 1, and

Fig. 3 shows the adjusting device of the hollow shaft in the disconnected condition.

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The driving shaft 1 is driven from a motor 6 through a chain wheel 2 by a chain 3 and a spur wheel drive 4, 5. The knife head 7 of a tobacco cutter is rigidly connected to the drive shaft 1. The drive shaft 1 with the knife head 7 is rotatably mounted in end bearings 1a, 1b (see Fig. 2). A hollow shaft 8 is disposed about the shaft 1 on one side of the knife head and said shaft 8 is provided externally for example with a worm ring 8. A worm Wheel 9 engages this worm ring which worm wheel is mounted on the shaft 10.

The shaft 10 rotates in bearings 10" which are rigidly mounted on the side wall 7 of the knife head. Worms 11 are secured to the other ends of the shafts 10 which transmit their movement in each case to a worm wheel 12 mounted on the shafts 11'. Worms 13 are also mounted on the said shafts 11' which each cooperate with a worm Wheel 14 mounted on the corresponding spindles 15. The spindles 15 incorporate threads each engaging a half nut 16 of known construction which in turn engage between the knife 17 concerned and transmit the movement thereto.

The worm ring 8' mounted on the hollow shaft 8 is held by a clamping device which comprises a housing secured to the machine frame in which a pin 18 is carried which is pressed in known manner by a spring 19 continuously towards a notch 20 in the hollow shaft 8. The pin 18 has a projection 18a at its inner end which is flattened at two sides (18d). If the knife head 7 rotates after engagement of the pin 18 in the hollow shaft 8, the worm wheel 9 rolls about the stationary worm ring 8, is driven thereby and transmits its rotation through the machine elements 11, 12, 13, 14 and 15 to the knives 17 so that these are continuously fed forward.

If however the pin 18 is withdrawn so that the projection 18a disengages the notch 20 of the hollow shaft 8- for this purpose the pin 18 is rotated through -the hollow shaft is released from the worm ring 8 and rotates with the shaft 1 together with the gear wheels 9 which do not now rotate about their own axes. Thereby the worm wheels 9 always remain in the same contact position without rotating. The feed of the knives 17 is therefore stopped.

What I claim is:

In a tobacco cutter, a frame structure, a rotary cutter head mounted in the frame structure, a plurality of knives adjustably mounted on said cutter head with their cutting edges adjacent the periphery thereof, individual feed screws operatively connected with each of said knives for advancing the same outwardly, a gear member connected to the feed screw, a gear element loosely mounted on the cutter head and arranged about the axis thereof, gearing drivingly connecting said gear element to said gear members, and a spring loaded detent carried by the frame structure adapted to engage the gear element and hold the same against rotation to cause said gearing to drive said feed screws.

Dearsley Mar. 27, 1951 Schreiber Oct. 21, 1952 

